Alexander Veis

Bone Regeneration Using B-Tricalcium Phosphate in a Calcium Sulfate Matrix

The aim of the study was the histomorphometric comparison of the osteogenic potential of beta-tricalcium phosphate (beta-TCP) alone or in a calcium sulfate matrix. Three round defects, 10 mm (diameter) x 5 mm (depth), were created on each iliac crest of 4 dogs. The defects were divided into 3 groups. Ten defects were filled with beta-TCP in a calcium sulfate (CS) matrix (Fortoss Vital; group A), 10 defects were filled with beta-TCP alone (Fortoss Resorb; group B), and 4 defects were left ungrafted to heal spontaneously (group C). All defects were left to heal for 4 months without the use of a barrier membrane. Histologic evaluation and morphometric analysis of undecalcified slides was performed using the areas of regenerated bone and graft remnants. All sites exhibited uneventful healing. In group A sites (beta-TCP/CS), complete bone formation was observed in all specimens, graft granules dominated the area, and a thin bridge of cortical bone was covering the defect. Group B (beta-TCP) defects were partially filled with new bone, the graft particles still dominated the area, while the outer cortex was not restored. In the ungrafted sites (group C), incomplete new bone formation was observed. The outer dense cortical layer was restored in a lower level, near the base of the defect. The statistical analysis revealed that the mean percentage of new bone regeneration in group A was higher than in group B (49.38% and 40.31%, respectively). A statistically significant difference existed between the 2 groups. The beta-TCP/CS group exhibited significantly higher new bone regeneration according to a marginal probability value (P = .004 < .05). The use of beta-TCP in a CS matrix produced significantly more vital new bone fill and preserved bone dimensions compared with the use of beta-TCP alone.

A Case Report of a Compound Odontoma Causing Delayed Eruption of a Central Maxillary Incisor: Clinical and Microscopic Evaluation

A case of a compound odontoma caused delayed eruption of a central incisor in the maxilla is presented with clinical, radiographic, and microscopic findings. The odontoma was surgically removed and microscopic examination showed a lot of crown-like structures in a very irregular form, some of which were fused to each other at their apical parts. Enamel and pre-enamel were totally abnormal, whereas the inside of the pulp chamber tissue did not present any histological sign of functional tissue. The most homogeneous tissue was dentin. The removal of the odontoma was followed by a rapid eruption of the impacted central incisor.

Bone Regeneration Around Implants Using Spherical and Granular Forms of Bioactive Glass Particles

Purpose:It has been reported that previous Biogran® (3i Implant Innovations, Inc., Palm Beach Gardens, FL) can be converted in vitro into hydroxyapatite (Biogran II®) to accelerate new bone formation. The purpose of this study was to evaluate the bone regeneration around implants placed in critical-sized defects in rabbit tibia using granular and spherical forms of Biogran II® in regards to implant contact, bone-to-graft contact, bone graft area, and total bone volume. Materials and Methods:Twelve adult New Zealand rabbits were used, offering 24 surgical sites (1 in each tibia), where 6-mm round defects were created allowing the homocentric insertion of a screw type experimental implant with Osseotite® (3i Implant Innovations, Inc.) surface. Half of the defects (group A) were filled up with spherical and half (group B) with granular forms of Biogran II®. Ossix® (3i Implant Innovations, Inc.) membranes covered the surgical sites. Results:The histological evaluation after 8 weeks showed new bone formation in both groups, without any statistically significant differences in regards to bone-to-implant contact, bone-to-graft contact, bone graft area, and bone volume. Both dissolution of the outer shell and inner silica gel of the particles were observed mostly in spherical particles. In addition, new bone formation within the protected pouch interconnected with the surrounding new bone was observed exclusively in spherical particles of Biogran II®. Conclusion:Faster dissolution of both outer and inner portions of spherical particles of Biogran II® led to better integration with the surrounding new bone during an 8-week period of healing.

Evaluation of Vertical Bone Regeneration Using Block and Particulate Forms of Bio-Oss Bone Graft: A Histologic Study in the Rabbit Mandible

The aim of the present study was to evaluate histologically vertical bone regeneration outcomes after using bovine bone graft material in block and granular forms. The buccal bony plates of the outer mandibles of 10 New Zealand rabbits received Bio-Oss blocks that were immobilized using orthopedic mini-plates, and another 10 received granular forms that were gently packed and stabilized into the custom-made perforated metallic cubes. The mean graft area (GA), new bone area (NBA), bone-to-graft contact (BGC), and maximum vertical height reached by the new bone development (MVH) were histometrically evaluated and showed no significant differences between 2 graft types. The new bone was observed mostly close to the basal bone and developed penetrating the trabecular scaffold in the form of seams that covered the intralumen surfaces of the block type graft, while in the granular graft type the new bone was observed to grow between the graft particles usually interconnecting them. Either form of Bio-Oss was capable of providing considerable vertical bone augmentation.